DB code: S00297

RLCP classification 3.105.250000.48 : Transfer
CATH domain : Rossmann fold Catalytic domain

CATH domain Related DB codes (homologues) : Rossmann fold S00298

Uniprot Enzyme Name
UniprotKB Protein name Synonyms RefSeq Pfam
P69795 N,N''-diacetylchitobiose-specific phosphotransferase enzyme IIB component
PTS system N,N''-diacetylchitobiose-specific EIIB component
NP_416252.1 (Protein)
NC_000913.2 (DNA/RNA sequence)
YP_489999.1 (Protein)
NC_007779.1 (DNA/RNA sequence)
PF02302 (PTS_IIB)
[Graphical View]

KEGG enzyme name
protein-Npi-phosphohistidine---sugar phosphotransferase
glucose permease
PTS permease
phosphotransferase, phosphohistidinoprotein-hexose
enzyme IIl4ac
gene glC proteins
gene bglC RNA formation factors
PEP-dependent phosphotransferase enzyme II
PEP-sugar phosphotransferase enzyme II
phosphoenolpyruvate-sugar phosphotransferase enzyme II
phosphohistidinoprotein-hexose phosphotransferase
phosphohistidinoprotein-hexose phosphoribosyltransferase
phosphoprotein factor-hexose phosophotransferase
protein, specific or class, gene bglC
ribonucleic acid formation factor, gene glC
sucrose phosphotransferase system II
protein-Npi-phosphohistidine:sugar N-pros-phosphotransferase
protein-Npi-phosphohistidine:sugar Npi-phosphotransferase

UniprotKB: Accession Number Entry name Activity Subunit Subcellular location Cofactor
P69795 PTQB_ECOLI Protein EIIB N(pi)-phospho-L- histidine/cysteine + sugar = protein EIIB + sugar phosphate. Monomer, in both its unphosphorylated and phosphorylated forms. Cytoplasm.

KEGG Pathways
Map code Pathways E.C.
MAP00010 Glycolysis / Gluconeogenesis
MAP00051 Fructose and mannose metabolism
MAP00052 Galactose metabolism
MAP00053 Ascorbate and aldarate metabolism
MAP00500 Starch and sucrose metabolism
MAP00530 Aminosugars metabolism

Compound table
Substrates Products Intermediates
KEGG-id C04261 C11477 C00615 C00934
Compound Protein N(pi)-phospho-L-histidine Sugar Protein histidine Sugar phosphate
Type aromatic ring (with nitrogen atoms),peptide/protein,phosphate group/phosphate ion polysaccharide aromatic ring (with nitrogen atoms),peptide/protein phosphate group/phosphate ion,polysaccharide
1e2bA Unbound Unbound Unbound Unbound
1iibA Unbound Unbound Unbound Unbound
1iibB Unbound Unbound Unbound Unbound
1h9cA Unbound Unbound Unbound Unbound

Reference for Active-site residues
resource references E.C.
Swiss-prot,Phosphorylation site

Active-site residues
PDB Catalytic residues Cofactor-binding residues Modified residues Main-chain involved in catalysis Comment
1e2bA mutant C10S
1iibA mutant C10S
1iibB mutant C10S
1h9cA CSP 10 CSP 10 (phosphorylated cys) phosphorylation site

References for Catalytic Mechanism
References Sections No. of steps in catalysis

Medline ID
PubMed ID 2092358
Journal Res Microbiol
Year 1990
Volume 141
Pages 1061-7
Authors Reizer J, Reizer A, Saier MH Jr
Title The cellobiose permease of Escherichia coli consists of three proteins and is homologous to the lactose permease of Staphylococcus aureus.
Related PDB
Related UniProtKB P69795
Medline ID
PubMed ID 8003964
Journal Protein Sci
Year 1994
Volume 3
Pages 282-90
Authors Ab E, Schuurman-Wolters GK, Saier MH, Reizer J, Jacuinod M, Roepstorff P, Dijkstra K, Scheek RM, Robillard GT
Title Enzyme IIBcellobiose of the phosphoenol-pyruvate-dependent phosphotransferase system of Escherichia coli: backbone assignment and secondary structure determined by three-dimensional NMR spectroscopy.
Related PDB
Related UniProtKB P69795
Medline ID
PubMed ID 9041631
Journal Protein Sci
Year 1997
Volume 6
Pages 304-14
Authors Ab E, Schuurman-Wolters G, Reizer J, Saier MH, Dijkstra K, Scheek RM, Robillard GT
Title The NMR side-chain assignments and solution structure of enzyme IIBcellobiose of the phosphoenolpyruvate-dependent phosphotransferase system of Escherichia coli.
Related PDB 1e2b
Related UniProtKB P69795
Medline ID
PubMed ID 9032081
Journal Structure
Year 1997
Volume 5
Pages 217-25
Authors van Montfort RL, Pijning T, Kalk KH, Reizer J, Saier MH Jr, Thunnissen MM, Robillard GT, Dijkstra BW
Title The structure of an energy-coupling protein from bacteria, IIBcellobiose, reveals similarity to eukaryotic protein tyrosine phosphatases.
Related PDB 1iib
Related UniProtKB P69795

The same E.C. number ( appears in D00527, D00525, S00283, S00420, S00046. All of them are enzymes in PTS system.
In the phosphotransferase (PTS) system, a phosphoryl group is transferred from phosphoenolpyruvate (PEP) via the PTS enzymes, EI, HPr, IIA, IIB to the tranported sugar. The enzyme here is IIB subunit of a cellobiose transporter (IIB-cellobiose).
The transfer of the phosphoryl group proceeds via an associative mechanism with a pentavalent phosphorus intermediate. Although positively charged residues are usually important for the stabilization of the negatively charged reaction intermediate, IIB-cellobiose lacks not only such residues but also any other positively charged residues. This suggests that in the phosphotransfer reactions between IIA-cellobiose and IIB-cellobiose, and between IIB-cellobiose and the translocated cellobiose, stabilization of the respective transition states is carried out by residues located on IIA-cellobiose and the membrane-bound IIC-cellobiose, respectively.

Created Updated
2002-07-27 2009-03-04